Corn-like mesoporous SnO2 /α-Fe2O3 heterostructure for superior TEA sensing performance

Corn-like mesoporous SnO2/α-Fe2O3 heterostructure was successfully prepared via a simple one-step hydrothermal route. A large number of nanotubes with the average diameter of about 15 nm grew on the surface of the composites. The influence of Sn4+ initial concentration on the morphology, structure and gas-sensing performance of all products was studied. The gas-sensing test indicated that SnO2/α-Fe2O3-5 (the molar ratios of Sn4+/Fe3+ was 5:100) based sensor displayed high response value (76) to 100 ppm TEA, superior selection than that of SnO2, α-Fe2O3 and other SnO2/α-Fe2O3 composites. The outstanding gas-sensing properties could be due to unique corn-like mesoporous SnO2/α-Fe2O3 composites with nanotubes, the formation of n–n heterojunction between α-Fe2O3 and SnO2, large specific surface area and the change of carrier concentration caused by the implantation of Sn4+ into α-Fe2O3 nanostructure.